In a post about its new London base, the company said, “London is a perfect fit for Facebook engineering – it’s a global hub, and it has a vibrant local startup community with lots of great technical talent. Our team in London will start small, focusing on building a core of great engineers, and then grow over time and eventually focus on building products in key areas like mobile and platform.”

So if you’re thinking of Facebook as a future employer, a day spent hacking in its offices might provide a sense of what it is like to work there.

The event page on Facebook says that the hackathon is open to all and especially invites those who are new to the company’s APIs.

It looks as though it’s going to be a neat day with several sessions including how to integrate your app with Open Graph, the platform for iOS and Android apps and how to build games with Facebook. Lunch and dinner is laid on and the whole afternoon is set aside for hacking.

Attendees can choose to attend the sessions or get straight into hacking on arrival if they feel like it. The Facebook London engineering team will be on hand to answer questions and offer guidance along the way.

As usual with the hackday format, there will be presentations, judging and prizes at the end of the day.

If you’re up for a bit of Facebook hacking, you can register for the event here and then head to the new London offices on Friday 21st.